What is Cancer Screening?
Checking for disease when there are no symptoms. Since screening may find diseases at an early stage, there may be a better chance of curing the disease. Examples of cancer screening tests are the mammogram (for breast cancer), colonoscopy (for colon cancer), and the Pap test and HPV tests (for cervical cancer).
Dangers of Screening: Overdiagnosis and Overtreatment
Definition of Overdiagnosis
Source: National Cancer Institute
Finding cases of cancer with a screening test (such as a mammogram or PSA test) that will never cause any symptoms. These cancers may just stop growing or go away on their own. Some of the harms caused by overdiagnosis are anxiety and having treatments that are not needed.
Some cancers that are diagnosed early do not develop symptoms requiring treatment, while others grow so slowly that the patient outlives the cancer and dies of other causes. Many of these are treated unnecessarily, leading to:
- Unnecessary tests and treatment
- Exposure to dangerous side-effects
- Radiation-induced cancers
- Mental and physical pain
- Inflated survival rates
This 2019 Opinion Article says: For cancer screening to be successful, it should primarily detect cancers with lethal potential or their precursors early, leading to therapy that reduces mortality and morbidity.
Screening programmes have been successful for colon and cervical cancers, where subsequent surgical removal of precursor lesions has resulted in a reduction in cancer incidence and mortality.
However, many types of cancer exhibit a range of heterogeneous behaviours and variable likelihoods of progression and death. Consequently, screening for some cancers may have minimal impact on mortality and may do more harm than good.
Prostate, Breast, Renal, Thyroid cancers, and Melanoma
This 2020 study found: After analysing changes in absolute lifetime risks for prostate, breast, renal, thyroid cancers and melanoma between 1982 and 2012, we estimated that 18% of all cancers diagnosed in women (ie, 11 000 diagnoses each year), and 24% of those in men (18 000 each year) are overdiagnosed cancers.
Swiss medical board call for end to mammography screening
In 2013, the Swiss Medical Board recommended that Mammography Screening be abolished in Switzerland ( The New England Journal of Medicine ) because of the emerging evidence that the harms of mammography outweigh the benefits.
The view of some health professionals
In an interview with National Public Radio, Donald Lannin, a professor of surgery at the Yale School of Medicine, who led the study, said “It takes 15 or 20 years for [these small tumors] to cause any problems. And you can kind of imagine that a lot of patients will die of something else over that 15 or 20 years.
That means a significant proportion of women who get screened for breast cancer with a mammogram go through biopsies, surgery, chemotherapy, radiation — and experience a lot of stress — for tumors that may never pose a health threat.”
In the same interview, H. Gilbert Welch, a professor of medicine, community and family medicine at Dartmouth College, who was not involved in the study, said “It appears that screening disproportionately finds good cancers — cancers that may be better off not found,”.
“I think that we all need to realize that we’ve probably oversold the idea that looking for cancer early is the best way to avoid it,” Welch says. “Mammography’s a really close call. It’s a choice. We’ve exaggerated its benefit and we’ve sort of understated its harms.”
This is an eye-opening documentary on breast screening.
Get the full documentary at thepromisefilm.net
No Mortality Benefit of Breast Cancer Mammography Screening in 25-Year Follow-up of Canadian National Breast Screening Study
By Matthew Stenger
Source: The ASCO Post
Mammography Screening Reconsidered
Anthony B. Miller, MD
As reported in BMJ by Anthony B. Miller, MD, Professor Emeritus at the Dalla Lana School of Public Health, University of Toronto, and colleagues, the 25-year follow-up of the Canadian National Breast Screening Study has shown no mortality benefit of annual mammography screening for breast cancer compared with physical examination or usual care. Mammography screening was associated with substantial overdiagnosis…
…By the end of the 5-year screening period, there were 142 excess cases of breast cancer in the mammography group (666 vs 524). At 15 years after enrollment, the excess number of cancers in the mammography group became constant at 106 cancers. The excess number represents 22% (106/484) of all screen-detected cancers. Thus, there was one case of overdiagnosis of breast cancer for every 424 women screened by mammography during the trial.
The investigators concluded, “[O]ur data show that annual mammography does not result in a reduction in breast cancer specific mortality for women aged 40 to 59 beyond that of physical examination alone or usual care in the community. The data suggest that the value of mammography screening should be reassessed.”
Continue reading at The ASCO Post
1. Reclassification of some “cancers”
Renaming low risk conditions labelled as cancer
Removing the cancer label in low risk conditions that are unlikely to cause harm if left untreated may help reduce overdiagnosis and overtreatment…Evidence is mounting that disease labels affect people’s psychological responses and their decisions about management options. The use of more medicalised labels can increase both concern about illness and desire for more invasive treatment.
This study says: A vast range of disorders—from indolent to fast-growing lesions—are labelled as cancer. Therefore, we believe that several changes should be made to the approach to cancer screening and care, such as use of new terminology for indolent and precancerous disorders. We propose the term indolent lesion of epithelial origin, or IDLE, for those lesions (currently labelled as cancers) and their precursors that are unlikely to cause harm if they are left untreated.
2. Alternative Screening Method: Digital Infrared Imaging (Thermography)
DII as a risk marker for breast cancer
Studies show that an abnormal infrared image is the single most important marker of high risk for developing breast cancer, 10 times more significant than a family history of the disease (5). Consequently, in patients with a persistent abnormal thermogram, the examination results become a marker of higher future cancer risk (4,5). Depending upon certain factors, re-examinations are performed at appropriate intervals to monitor the breasts. This gives a woman time to take a pro-active approach by working with her doctor to improve her breast health. By maintaining close monitoring of her breast health with infrared imaging, self breast exams, clinical examinations, mammography, and other tests, a woman has a much better chance of detecting cancer at its earliest stage and preventing invasive tumor growth.
Angiogenesis, or new blood vessel formation, is necessary to sustain the growth of a tumor. Digital Infrared Imaging may be the first signal that such a possibility is developing .
See full article at breastthermography.com
Where can I get this test?
This test is now available at numerous medical facilities including:
Hollywood Health (Northern Ireland)
Breast Thermography (list of testing centers country-wide
Molecular Breast Imaging: Potential New Tool for Detecting Cancers
Source: Oxford Journals
Mammography may be a “gold standard” for breast cancer screening, but for some women, its interpretation amounts to little more than a coin flip. In women with dense breasts, which contain more stromal and epithelial tissues than fat, interpretation of mammograms is difficult. Among these women, tumor detection rates with mammography barely exceed 60%. Both tumors and breast tissues appear white on a mammogram, but fat looks black. Clinicians can easily detect cancerous lesions against the darker fat backdrop, whereas dense tissues obscure tumors that could be life threatening.
Now researchers at the Mayo Clinic in Rochester, Minn., say that a different screening method— molecular breast imaging (MBI)— may offer a promising alternative for women with dense breasts, who make up much of the female population. Deborah Rhodes, M.D., an assistant professor at the Mayo Clinic, said roughly a quarter of all women older than 40 years have breast tissue that is more than 50% mammographically dense.
Compared with mammography, she said, MBI detected three times as many cancers among a population of 940 dense-breasted women who also had at least one additional breast cancer risk factor, such as a family history of the disease. These preliminary findings, announced in September at the American Society of Clinical Oncology’s 2008 Breast Cancer Symposium in Washington, D.C., came from an ongoing, comparative study of MBI and mammography that was launched at the Mayo Clinic in 2005. “We’re talking about a supplement to mammography that could be readily adopted by communities, instead of just major academic institutions,” said Rhodes, who is also the study’s principal investigator. “While [mammography is] terrific for some women, it doesn’t work well for others. For them, we need a better test, and that’s what MBI could provide.”
Read more at Oxford Journals